Vol 20, No 3 (2017)
- Year: 2017
- Articles: 15
- URL: https://journals.ssau.ru/pwp/issue/view/371
Articles
Mathematical models of broadband vibrator antennas
Abstract
Questions concerning the use of integral representations of the electromagnetic field for constructing self-sufficient mathematical models of broadband vibrator antennas are considered. The results of the numerical solution of the internal and external problem for some models of broadband vibrators are presented, as well as the results of calculating their input resistance in the frequency band.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Prospects of using metamaterials in the new generation antennas
Abstract
The article gives an overview of existing studies on the possibilities of using metamaterials in antenna technology, as well as a number of new studies by the authors. The prospects of using metamaterials in the design of antenna systems for improving their electrical and mass-dimensional characteristics are substantiated.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Dual-polarized radiator with high isolation for phased antenna arrays
Abstract
We propose the small-size dual-polarized radiator with high isolation. It is intended for use in a phased array with a wide scanning sector. Such radiator can also be used to construct an active phased array for satellite radars with synthesized aperture. The geometrical parameters of the radiator and the four-element module, as well as their general antenna characteristics have been optimized. The optimization results for the main characteristics of the radiator and the four-element module (VSWR, coefficient of isolation, directivity, radiation pattern shape) have been shown in the 6% frequency band, operating in the X-range.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
The experimental assessment of quality of measurement of coordinates and identifications of sources of radio-frequency radiation of high frequencies range
Abstract
The pilot studies of quality of measurement of coordinates and identifications of sources of radio-frequency radiation with the fixed values and pseudorandom reorganization of operating frequencies in the goniometric and goniometric and range-metering systems of high frequencies range are conducted. Regularities of change of mean squared errors of estimates of coordinates of objects in different season and days and also increase in probability of their correct identification are revealed in case of the fixed probability of false alarm due to reduction of sectors of viewing angles and the range of operating frequencies of direction finders.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Diffraction problem of electromagnetic wave propagation on system of arbitrary located screens and bodies
Abstract
Diffraction problem of electromagnetic wave propagation on system of arbitrary located screens and bodies is considered. Uniqueness and solvability theorems are proved. The problem is reduced to the integro-differential equations in Sobolev spaces. Solvability of system of integro-differential equations is proved also.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Microwave photonic crystals with electrically controlled characteristics
Abstract
The results of investigations of waveguide and microstrip photonic crystals with electrically controlled characteristics have been presented. The designs of photonic crystals with electrically controlled characteristics based on microstrip lines and waveguides with dielectric filling, with resonant diaphragms and frame elements, which can be used both for the creation of microwave switches, selectors, signal modulators, and high-sensitivity systems for measuring materials parameters at microwaves have been proposed.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Propagation properties of waveform based on gaussian beams superposition
Abstract
The exact solution of parabolic wave equation based on localized in space-time superposition of Gaussian wave beams is discovered in the paper. Some special properties of waveform and its propagation are investigated. A possibility of practical application of focused wave beams and controlling their parameters for obtaining required waveform was considered.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
The effect of spatial dispersion on the optical properties of semiconductors and nanomaterials
Abstract
The report compares the behavior of the optical parameters of normal waves arising in a medium with spatial dispersion for a semiconductor material - the CdS crystal and the nanomaterial - silicene. It is noted that spatial dispersion should be taken into account when analyzing the reflection spectra near exciton resonance.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Application of multilevel modeling methods in the design of radio-frequency devices of radio-engineering systems
Abstract
In this paper, we propose a generalized algorithm for hierarchical multi-level modeling of radio-frequency devices of radio-engineering systems, which allows modeling methods to optimize the principle of radio-frequency devices constructing and its microwave components, electrical parameters of radio-frequency devices, technological processes of manufacturing microwave nodes and their elements.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Boundary value problem of finding the function of a source, creating a predetermined radiation field
Abstract
Is formulated self-consistently the problem of radiation, which leads to a system of homogeneous Fredholm integral equations of 2nd kind with respect to the fields over the aperture of the emitter. It is shown that this system of equations allows to determine the function of the source, creating a desired field of radiation. The problem of calculating the radiation field from the end of a round open dielectric waveguide. It is shown that for algebraically integral equations in problems of this type can be used successfully the collocation method are.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Complex resonance as a phenomenon described by a self-consistent adjoint boundary value problem
Abstract
A correspondence is established between the properties of a complex resonance and the singularities of non-self-adjoint self-consistent adjoint boundary-value problems. A phenomenon classified as a «complex resonance» takes place in electrodynamic structures described by non-self-adjoint boundary-value problems. It is shown that in the case of pair excitation of complex waves having complex conjugation in wave numbers and amplitudes, a vibration «attached» to the source is formed, which is described by the adjoint Helmholtz equation, that is, the equation on the right side of which is the solution of the homogeneous boundary value problem. A feature of complex resonance is that it exists in the entire range of complex waves with the obligatory presence of a source.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Mathematical models and pilot studies of antennas of the onboard equipment of system of video control of spacecrafts and accelerating blocks
Abstract
Article is devoted to creation of mathematical models and experimental working off of electric characteristics of antennas of the onboard equipment of video control of spacecrafts and accelerating blocks. Creation of mathematical models is carried out in HFSS on the basis of integral representations of the electromagnetic field. The question of optimization between the sizes of the antenna and the necessary direction characteristic with the decimeter L-wave range is considered. Results of numerical modeling and experimental datas for two samples of antennas are given.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
The stability and electromagnetic compatibility of power supply modules and systems
Abstract
The main questions for designing the power supply modules and systems are considered. They are the electromagnetic compatibility of power supply modules, the stability of power supply modules and the stability of whole power supply system.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
The device of correction of circadian rhythms of the person
Abstract
The article describes the connection between the secretion of melatonin and human circadian rhythms. The influence of blue light on the production of this hormone is considered. Particular attention is paid to the 440-460 nm band, whose emission spectrum is completely due to the spectrum of the action of photochemical damage to the retina of the eye. A description is given of the production of artificial white light in modern white LEDs. A modern application of light therapy for various purposes is described. The authors of the article developed and created a device for correcting circadian rhythms of a person that can change the level and spectral composition of light, thereby artificially adjusting the human biorhythm in rooms with insufficient natural light.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)
Calculation of color differences between two colors
Abstract
In this paper, we consider the problem of computing color differences between two specified colors in the existing color systems by international Commission on illumination, or as to the accuracy of the color differences obtained by using specific formulas: JPC-79; CMC-based JPC-79 developed by the Committee on colorimetry of the Royal society of dyers and colourists; and the formula recommended in 1994 by international Commission on illumination. At the time, one of the authors (Prof. Lozhkin L.D.) was offered strictly equicontrasting color system, protected by a patent for an invention, but this system was applied to rather complicated mathematical apparatus, based on tensor calculus. This work uses a simple method of calculating color differences, and a fairly simple mathematical apparatus. The results of calculating color differences between two specified colors. This was specially created computer program that allows you to calculate color differences.
![pages](/img/style/pages.png)
![views](/img/style/views.png)
![](/img/style/loadingSmall.gif)